In the UK, one in four adults over 65 have depression (Fancourt & Tymoszuk, 2019), while a third of older adults in the UK report loneliness (Victor et al., 2021); defined here as the difference between a person’s desired social relationships and the relationships they see themselves having. Existing research has also indicated an increased risk of depression in people who feel lonely across all ages (Beutel et al., 2017). Loneliness can also be a pathway to many physical diseases, such as cancer, cardiovascular disease and dementia (Mann et al., 2017). We know that there are interventions able to reduce loneliness (Beutel et al., 2017), while this study suggests that these interventions could reduce the risk of developing depression.

Little research looks at loneliness and depression specifically in older people. This is an issue, particularly due to existing evidence suggesting that older people are more likely to have physical and mental health problems, live alone and not engage in physical or digital activities. All of these factors can result in being more socially isolated and vulnerable. Research looking into whether loneliness and social isolation are more likely to lead to depression in older populations could have important implications for how to support older people in the community.

The study discussed here by Lee and colleagues (2021) aimed to investigate whether loneliness is associated with subsequent depressive symptoms. They tackled methodological issues affecting previous research by using a large sample of adults over 50, a long follow-up period of 12 years, a longer loneliness questionnaire and measured social factors, such as social isolation and social support.

Methods

Between 2004 and 2017, a sample of people aged 50 years or older in the UK were contacted every 2 years to take part in the study. The sample was thought to be representative of other people of this age. Every two years they took part in face-to-face interviews and completed questionnaires. The questionnaires asked about their depressive symptoms in the past week, using the Centre for Epidemiologic Studies Depression Scale (CES-D) and about their experiences of loneliness, using the R-UCLA; University of California, Los Angeles Loneliness Scale.

The CES-D also explored whether the depressive symptoms the individual experienced met a formal diagnosis of depression. In addition, loneliness was measured using three questions:

• How often do you feel you lack companionship?
• How often do you feel left out?
• How often do you feel isolated from others?

Loneliness was studied from the point of view of the participants and not by using the objective number or quality of their social relations.

The researchers collected information about the person’s social network size, frequency of social contact, participation in social groups and their own perspective of how much social support they have, to see if any of these might independently be increasing a person’s risk of depression and loneliness. Statistical analysis was used to estimate how much the experience of loneliness had contributed to a person’s risk of depression.

Results

The total sample was 9,171 people, but full data sets were not available for many of them, so only 4,211 participants were included in the final sample and analysis.

What do we know about the characteristics of participants?

• Average age was 65.1 years (range 52-101 years)
• 100% were from a white background
• 55% were female
• 66% were unemployed or retired

What were the results in relation to depression and loneliness?

• The researchers discovered that the link between depression and loneliness was greater than by chance alone.
• Lonely people were more likely to develop depression later on. This was true even when statistically accounting for other factors that might affect this link, so it is highly likely that loneliness may lead to depression.
• The more lonely people felt, the worse their symptoms of depression; every time a person’s loneliness score went up by one, their depression score also went up (by 0.38).
• The final follow-up suggested that 11 to 18% of cases of depression could potentially be prevented by eliminating loneliness.

Conclusions

A group of researchers from University College London, followed up 4,211 people over 12 years. They found that older people are more likely to develop depression if they have felt lonely. In fact, 11-18% of cases of depression could be prevented if loneliness was eliminated.

Strengths and limitations

The study has many strengths, including:

• This is the first study to use a large sample of people over a long period of time to explore loneliness and depression in older people, which helps us to better understand the association between loneliness and depressive symptoms
• Depression and loneliness were measured with widely used and validated questionnaires in older adults
• The questionnaire for depressive symptoms was used at each follow up, which helps people answer more truthfully
• Other social (e.g. size of social circle, how often people see their social circle), personal (e.g. age, gender, employment status) and genetic factors that can affect the relationship between loneliness and depression were taken into account
• It used a sample that was representative – from a large nationally representative annual household survey monitoring population health trends.

However, some limitations do exist:

• Only people living in private households in England took part in the study, which means that the results may not apply to those living in non-private households (e.g. care homes) or other parts of the world
• Only white people were involved in the study, so the results may not apply to people from ethnic minorities
• As the study progressed, people were getting older, so there was a lack of data for the younger age ranges. The researchers addressed this by ‘refreshing’ or adding new participants from the younger age range at later time points. Since the study took place between 2002 and 2017, life for those joining later would have been different e.g. changes in technology means that people can see friends and family virtually
• The average age of the sample was 65, so it may not be representative of the ‘older end’ of the range
• Questionnaires were completed every 2 years for the previous week, but this may not reflect how people felt for the rest of the two years
• The loneliness questionnaire focused on emotional loneliness (not having a deep connection with at least one other person) and not social loneliness (not having a wide social circle), which may have a different relationship with depression
• The researchers used a statistical method for missing data and assumed data was missing at random to calculate this, but we cannot ensure that this reflects the actual data
• People with more severe loneliness and depressive symptoms are more likely to drop out from the study over time and the researchers didn’t take this into account in their analysis. This may have reduced the strength of the relationship between loneliness and depression

Implications for practice

This study shows that there is a link between loneliness and depression irrespective of people’s other social experiences. Loneliness can be reduced by interventions that encourage social support through meaningful connection, quality relationships, empathy and belongingness. These same interventions could help reduce depression in older populations. Clinicians may increase their awareness about the risk faced by older people experiencing loneliness and their possibility of developing depression. Given that a third of people over 50 years old experience loneliness, these findings could affect a high proportion of patients clinicians see by providing good community links and delivering community-based interventions.

Many questions remain about this emerging field of research:

• Is it possible to eliminate loneliness? And how, given it is a subjective experience?
• What about loneliness of younger populations and those with and without relationships?
• What are the effects of loneliness on our physical health?

In recent years there has been growing interest in social prescribing. However, a whole new infrastructure would be needed to create opportunities for those in need in the community. We need more research into social prescribing, social skills training and supported socialisation. If we succeed to create an environment which encourages human interaction and fosters the development of relationships, there is a good chance this will help reduce the burden of depression and may also improve physical health amongst older adults and the wider population.

Statements of interest

None.

Contributors

Thanks to the UCL Mental Health MSc students who wrote this blog from Pearce Group: Kate Adlington (@kateadlington), Tia Urgasova (@tiaurgasova), Hana Afrah, Magdalena Tomaskova (@MentalHResearch), and Olubunmi Funmilayo Kusoro (@olubunmi_kusoro).

UCL MSc in Mental Health Studies

This blog has been written by a group of students on the Clinical Mental Health Sciences MSc at University College London. A full list of blogs by UCL MSc students from can be found here, and you can follow the Mental Health Studies MSc team on Twitter.

We regularly publish blogs written by individual students or groups of students studying at universities that subscribe to the National Elf Service. Contact us if you’d like to find out more about how this could work for your university.

Links

Primary paper

Long Lee, S., Pearce, E., Ajnakina, O., Johnson, S., Lewis, G., Mann, F. … Lewis, G. (2021). The association between loneliness and depressive symptoms among adults aged 50 years and older: a 12-year population-based cohort study. Lancet Psychiatry, 8, 48-57.

Other references

Fancourt, D., & Tymoszuk, U. (2019). Cultural engagement and incident depression in older adults: evidence from the English Longitudinal Study of Ageing. The British Journal Of Psychiatry, 214(4), 225-229.

Katsampa, D. (2019, August 9). Can cultural activities protect people against depression in older age?. Mental Elf. Last accessed: 08/02/2021

Victor, C.R. & Yang, K. (2021). The prevalence of loneliness among adults: A case study of the United Kingdom. The Journal of Psychology, 146(1-2), 85-104. doi:10.1080/00223980.2011.613875

Beutel, M. E., Klein, E. M., Brähler, E., Reiner, I., Jünger, C., Michal, M., . . . Tibubos, A. N. (2017). Loneliness in the general population: Prevalence, determinants and relations to mental health. BMC Psychiatry, 17(1). doi:10.1186/s12888-017-1262-x

Mann, F., Bone, J.K., Lloyd-Evans, B., Frerichs, J., Pinfold, V., Ma, R. … Johnson, S. (2017). A life less lonely: the state of the art in interventions to reduce loneliness in people with mental health problems. Soc Psychiatry Psychiatr Epidemiol 52, 627–638. doi.org/10.1007/s00127-017-1392-y

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